QUANTITATIVE ESTIMATION OF CHITIN AND PROTEINS IN THE CUTICLE OF 5 SPECIES OF PRIAPULIDA

The biochemical composition of the cuticle of 5 species of Priapulida was tested using a specific enzymatic method for the determination of chitin, and a lectin-labelling technique for its ultrastructural locat ion. The integument of all species tested contains 4-15% chitin and 9- 85% protein. Chitin could be located in both layers of the priapulid c uticle, even though their ultrastructural morphology differs. The resu lts of this work suggest a close relationship between the Priapulida a nd the Kinorhyncha, the only other group of Aschelminths known to have a chitinous cuticle.